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Re: "Bit" size and printing...

1. It's my understanding that most (not all) printers print in 8 bit no matter what you send to them, which is probably why your lab said what they did. But apart from that, I don't think there's any advantage to sending a 16 bit file to the printer - 16 bits is important for editing but I'd be surprised if you noticed any difference between sending an 8 bit file or a 16 bit file to the printer even if the printer was capable of printing in 16 bits. I've seen heated arguments about this point but generally it was one person saying he or she saw a difference vs 10 saying there was no difference.

2. 300 bits is a common number. I'd suggest trying different size prints at differnt dpi and see what you get. When I attended his workshop George deWolfe said that tests run by a consortium consisting of him and a bunch of other notables showed that 420 bits or something like that was the optimum number but I've never aimed for that number myself.

3. I don't know that the file format matters solely for printing. But I save all files as tifs so that's what I send to the printer.

There are people here who know more than I do about all this stuff, I'm still learning. If one of them contradicts anything I've said here ignore what I've said and listen to what they say.

Brian Ellis
Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
a mile away and you'll have their shoes.

Re: "Bit" size and printing...

Each digital printer and specific models, be it Noritsu or Frontier or whatever, have a specific dpi that is optimal for output. Ask your lab for all the specifics...

If you order online from Adorama, WHCC or elsewhere, there is usually a web page that lists the exact format and resolution that they need to optimally print your image, or you can email them for the info...

So, yes...8 bit, usually 300 (but check to make sure, some printers like to see odd numbers), and TIF or JPG are usually the standard.

Re: "Bit" size and printing...

Hi Brian, PV, Robert,

Thanks for your input...

How about scanning B&W negs... do you scan yours in 8 or 16 bit? My understanding is that you pull more detail/information off the neg with 16 bit. But, the file sizes are huge relative to scanning them in 8 bit.

Re: "Bit" size and printing...

1. What bit size do you have the lab print in? For example, I took some discs in to the lab and they said they don't print in 16 bit sizes.

2. What dpi are you using most commonly for a maximum image size of 16x20? In the past, I've used 300 dpi. However, is there any advantage to using something higher?

3. Lastly, what format (Tiff, jpeg, etc) works best for your printing needs? Any suggestions?

All these depend on what machine your lab uses as a printer.

1) Most printer drivers want 8 bit files. Most of the drivers will compress 16 bit files on the fly to 8 bit. Some will not. Newer machines like the new Canon wide format printers have 16 bit drivers available. Ask your lab for specifics on what they want from you. If they don't know, find a lab that does.

3) Once again, it depends on your lab. Ask them what file format they want your file to be in.

While you are asking the lab questions, ask them for an ICC profile so you can soft proof on your home PC. Ask them what color space they want the file to be in. Most will want Adobe RGB 1998, some can handle bigger spaces like ProPhoto RGB. I would worry about the ones that want sRGB because it is too restrictive for my tastes.

Then, ask them if there's anything else they want from you that you haven't asked about yet. All this in the name of proper communication between the two of you so that you both get what you want.

Re: "Bit" size and printing...

Originally Posted by Capocheny

How about scanning B&W negs... do you scan yours in 8 or 16 bit?

I scan B&W negatives only in 16 bit. Yes the file size is exactly twice as big vs. 8 bit files. Put another way, the file size is 1/3 that of 16 bit color scans. As the Borg would say, size is irrelevant.

Every image I've scanned has needed some editing. Some small, most somewhat more. It's the ones that have more than "small" editing that need the 16 bits. Even medium changes in 8 bits can give you posterization. And with B&W you don't have color to hide behind --- everything is visible, including the smallest amount of posterization.

Re: "Bit" size and printing...

Our Lambda prints at 200ppi and at 400ppi , it is a 8bit printer.
As others have noted image editing in 16bit is what most do, and we accept in either 16 or 8 bit.
There is a noticable difference at 400ppi. Before we purchased our own machine we rented time on another labs machine which ran at 200ppi, when we landed our own Lambda we switched to 400ppi . It takes twice the time to expose but we see the difference.
It becomes problematic when clients capture with small files and want to push the print size up and up. *mostly posterization like* abberations in the highlight region.

Re: "Bit" size and printing...

There is a difference between 16-bit grayscale and 16-bit RGB. They are both 16-bit per channel, but the difference is that grayscale has only one channel and RGB has three. The amount of information is not tripple, however, but exponential, since 16-bits equal to 2^16 = 65,536 and the amount of information in the 3-channel RGB file is actually 65,536^3 (to the power of 3), not 65,536x3. That's billions of shades.

Therefore, even if you scan and process a b&w image, you have that much more information to work with (and can afford to loose during editing) if you acquire and edit in 16-bit RGB until the very end, when you convert to 8-bit RGB for printing.

To make this last bit clear, it is more beneficial to keep the b&w file in RGB for printing as well, because the same math applies. Instead of 2^8 = 256 shades of gray in a grayscale 8-bit file, you end up with (2^8)^3 = 256^3 = approx. 16 million shades of gray for the printer to render.